By Mario Trujillo - 06/06/14 08:35 AM EDT
Nonetheless, Clapper said, the damage is still "profound."
A year has passed since the first stories were published about secret NSA surveillance programs, based on documents leaked by Snowden. It is still unclear how many documents he took.
In a recent interview with NBC, Snowden said the NSA still does not know because its auditing was so poor. He maintains he no longer has or can access any of the documents.
"Their auditing was so poor, so negligent, that any private contractor, not even an employee of the government, could walk into the NSA building, take whatever they wanted and walk out with it, and they would never know," he said.
Former NSA Director Keith Alexander said last month Snowden has "touched" more than a million documents, but "I don't think anybody really knows what he actually took with him because the way he did it."
"We know that he has given tens of thousands of documents to reporters, probably over 100,000, and maybe even much more than that," Alexander said at the time.
About 300 documents have been published by news organizations. A senior official told The Washington Post that the United States assumed he gave an additional 200,000 documents to reporters.
The official said there is another batch of nearly 1.5 million documents that Snowden touched that the United States assumed he has taken — down from a previous estimate of 1.77 million.